When the Department of Fish and Game tried to persuade Stockton developer Alex Spanos to set aside 600 acres of a proposed 1,300-acre development north of the city to preserve three nests of the rapidly disappearing Swainson's hawk, both the developer and the city rejected the request. The state agency did not sue to protect the hawks, one official said, because "We didn't have our act together. We just have too many projects to consider, and some things slip by us."

Daniel said Delta development also poses a threat to striped bass, salmon, Delta smelt and other species that have made the region a fisherman's paradise.

Other environmental problems are presented by the Delta's role as the key transfer point for Northern California water headed south. About 40% of all of California's fresh water supply flows out of the Sierra into the Delta.

In 1986, the California Supreme Court ruled that existing standards for Delta water salinity, temperature and toxic pollution were inadequate and ordered the State Water Resources Control Board to set new standards.

But after more than three years of studies and hearings, the board has been unable to agree on policies that both protect the Delta and also ensure an adequate flow of water through the huge state and federal aqueducts that take water south.

But the most dangerous problem presented by large-scale development in the Delta is flooding. Most of the 1,100 miles of levees in the region are aged structures built of peat and other unstable materials.

"Virtually every island in the Delta has failed (been flooded) in the last 100 years, some of them several times," said Curtis L. Fossum, senior staff counsel for the State Lands Commission.

Karl Winkler, chief of the Delta planning branch in the Department of Water Resources, said there have been 24 levee breaks in the Delta since 1980, costing more than $100 million to repair.

The Federal Emergency Management Agency, which administers the national flood insurance program, says the only levees in the entire region that meet federal standards are those at Discovery Bay.

Breaks are not the only danger. The old peat levees, many built by Chinese laborers in the 1800s for agricultural purposes, are subject to subsidence (that is, they sink into the soft peat below) and to "over-topping" (floodwaters simply rise too high and jump the levee banks, as they did in many Delta areas during the fierce winter storms of 1986).

To strengthen all Delta levees would cost at least $1 billion, said Ray Lenaburg, who oversees the national flood insurance program in FEMA's San Francisco office.

And if even the most cautious estimates of the effect of "global warming" are correct, then the flood danger in the Delta becomes more acute.

Studies indicate that "the existing problem of protecting low-lying lands in the Delta are going to be increased substantially, even if the lower range of the estimates of sea-level rise are used," said Phillip Williams, a consulting hydrologist from San Francisco.

Technically, it is possible to protect Delta lowlands against floods, but it would require "a huge investment," Williams added.

Developer L.E. (Bud) Weisenburg, who wants to breach a levee on Bethel Island and build 550 expensive waterfront homes, said the Delta flood threat has been exaggerated.

Weisenburg plans to move 3 million cubic yards of dirt and sand to build new levees that are 10 feet high and 270 feet wide at the base. Weisenburg says the levees will be impenetrable to flooding.

But Williams pointed out that if the levees are not as effective as Weisenburg believes they will be, or are damaged by an earthquake, "The developer will be long gone and the community will have to pay for any upgrading that is done."

"People who live here accept the flood danger," said Christine Thresh, secretary of the Bethel Island Municipal Improvement District.

But only about 2,500 people now live on the island and adjacent Hotchkiss Tract, while the planned new developments would increase the population to more than 17,000.

"Putting new (housing) units on an island that's entirely below sea level--that's crazy, it really is," said Sanders of the State Lands Commission.

Nevertheless, Delta builders and developers--and their allies on local planning commissions, city councils and county boards of supervisors--believe in development.

"I'd like to see a banner on the main street that says, 'Stockton is open for business!' " said Ron Coale, a member of the Stockton City Council. "We have the land, we have the labor. We are coming out of an agrarian society into a business society--the sooner we recognize that, the better off we'll be."

There are a few dissenting voices, including that of Barbara Fass, mayor of Stockton since 1985.